This has been rumored for some time now. Since Google has been leading the search engine market and MSFT and Yahoo have either stagnated or slowed, it was time to do something. Based on the
open letter from Steve Balmer to Yahoo's board, I don't see the synergies. Just on the Ad platform they now have to deal with two separate ones. How does this build synergies? As they transition people from one to the other, they could suffer heavy losses with people switching to Google. I would track the unique users number reported by comScore Media Metrix for the next several months. These numbers will tell us if the combined entity is able to make any inroads in terms of relevance.